Abstract: A method and apparatus for holding an electrically conductive workpiece in a machine tool by forming at least one positioning cavity or recess on a face of the workpiece by a holder having a tip used for machining the cavity or recess by a conventional EDM sinking operation. Subsequently to forming the cavity, the tip is used as one of the holding members for the workpiece. Two tips may be used to sink cavities or recesses on opposite surfaces of the workpiece, or the tips may take the form of fingers sunk into the workpiece from one side only. The tips form part of support members mounted on the end of displaceable arms for enabling the workpiece to be positioned relative to a tool or to be displaced. The tip-provided supports may be used for supporting a portion of the workpiece being cut off or severed from the workpiece.

Abstract: An EDM apparatus having a first support member for the workpiece and a second support member for the guide members of an electrode wire. A cross-slide provides relative linear motions between the two support members for effecting a cut in the workpiece by the electrode wire. A third support member carrying a form electrode tool is arranged to be selectively held stationary either relative to the first support member, by an appropriate first coupling member, or relative to the second support member, by a second coupling member. Under the first condition, the cross-slide provides the necessary relative linear displacements between the electrode wire and the form electrode tool for cutting the electrode tool by the electrode wire and, under the second condition, the same cross-slide provides the necessary displacements for sinking the electrode tool into the workpiece.